I have 8s as rears with my Theatre. The control panel does light up on the 8s and is functional. You can select favorites and adjust volume etc on the Theatre from the 8s. I don’t believe there is any way to listen to music just on the 8s although I have never tried.  I suppose it might be possible to create a listening position through the Theatre that includes only the 8s.

Yes, the plan was to have a listening position for music with only 8s as stereo, and “movie position” with theatre+8s as rears. Ok, great and good to know, thanks for writing!

Sorry for late reply. I’m usually in the BeoTalk Discord group and does not visit the Beoworld forum that often as I only have new Mozart speakers. Beoworld is much more focused on the older B&O equipment while BeoTalk has a lot more activity for the newer stuff. The sites complement each others.
I have a Theatre with Beolab 28 as fronts and Beolab 8 as surround (plus a pair of BL8 in my bedroom and a Beosound 2 in my kitchen).
I started of with Beolab 28 for two years ago (my first B&O equipment after 30 years with typical HiFi brands like B&W, Dali, Onkyo, Nad, etc), and have now committed wholeheartedly to B&O.
The behaviour of the Beolab 8s connected to the Theatre (or any other Mozart based speakers) is dependent on how you connect them.
Old analog PowerLink (PL) cables or wireless WiSA:

• The external speakers are connected/committed to the Theatre first when you turn on the Theatre. Then they become dumb speakers and you cannot use their touch interface for controlling your Theatre setup.

• However, when the Theatre is turned off, your Beolab 8s are available as separate speakers from the B&O app or any streaming app. Then the touch interface also works and you can control them as stand-alone speakers (like you didn’t have any Theatre at all).

 
If you instead connect the speakers to your Theatre with either wireless or wired Digital PowerLink (DPL), they behave as follows:

• They become an integrated part of your Theatre-system. The touch controls are always available to control the whole Theatre-system.

• The speakers disappear as stand-alone options to connect to in the B&O app or your streaming app. To play stereo music from only your connected Beolab 8s you create a Listening Position for your Theatre where you only allocate roles (front L/R) to your connected speakers, not to any of the inbuilt speaker elements in the Theatre. You can then decide that your favourite buttons on your speakers should use that Listening Position so that when you start some music from them, only your BL8s are used.

 
Personally I originally had my front BL28 connected with wired analog PL (the traditional “old” PowerLink connection) and the surround BL8 over WiSA. Since 6-8 months I changed the connections to wired DPL to my BL28 and wireless DPL to my BL8, and I could not be happier with my choice.
There are two main reasons why I changed to use the “new” Digital PowerLink connection.
1st reason: When using traditional analog PowerLink, I heard a clear difference in sound quality when I played music through the Theatre to my BL28 compared to connecting to my BL28 directly without going through the Theatre. The main difference was related to stereo imaging. When playing the BL28 I got imaging that was very detailed, I could really pinpoint every instrument and singer’s voice in the stereo track. When playing the BL28 from the Theatre (with a Listening Position that only used the BL28 and a Sound Mode with Direct sound path) the sound stage become more blurry and diffuse. I could not point out each voice and instrument as accurately anymore. With Digital PowerLink I cannot hear any difference going through the Theatre compared to playing the Beolab 28 directly (though not possible anymore when connected with DPL). The imaging and stereo soundstage is now once again extremely good on my Beolab 28s. I believe one reason for this is that you basically remove two digital/analog conversions when changing to DPL compared to PL.  The sound is processed digitally in the Theatre, and the Beolab 28/8 need to use a digital signal. With old PL connections the Theatre first converted the digital signal to analog, and transferred it to your Beolab speakers, then they had to convert it back to digital signal. With DPL you remove these digital-analog-digital conversions.
2nd reason: To be able to use the touch interface on my BL28s and BL8s to start up music from the favourite buttons, join music from other rooms, or just change volume when I want to play music from the living room system. With the old PL connections you could only use the touch interface on the Theatre, which in my case is located far less convenient compared to my external speakers that I walk by regularly.
 
So please try out Digital PowerLink if you haven’t done it yet.
 
The BL8 works fantastic as surround speakers for my setup. However, initially I thought they were too expensive for what surround channels provide in most film. I also listen 60-70% on music and 30-40% watching TV/movies. Nor does the regular setup in the Theatre use the surround speakers especially much when playing music (plus I often prefer listening to dedicated music in Direct mode, only using my Beolab 28). However what really created value for me was to setup a new Listening Position that I call 2*Stereo where I setup both the BL28s and BL8s as front L/R speakers and leave out the Theatre from any roles (though set the front BL28 slightly higher to still get the voices in front of me when sitting in my sofa). That is fantastic for creating an enveloping sound with same volume and sound from both front and rear of the room. And the BL8 and BL28 have such similar sound profiles that the transition when walking in the room is very seamless. I have programmed my favourite buttons to use this Listening Position when I want to start listening to music spontaneously.
For dedicated music listening I still prefer just using the regular 5.0 setup in Direct Mode so that only my Beolab 28s are used (except sometimes I allow bass management from the other speakers). However, in most of the cases (70-80%) I use this 2*Stereo Listening Position when listening to music. After finding this out I’m 100% happy that I invested in the BL8 as surround/rears.
 
Don’t hesitate to get back with other questions regarding the Theatre or connected speakers to it. I’m happy to help!

Hi Dominik. Not sure if my answer to you got tagged as an answer. So please see my answer in my message above. 😀

Dear Bill,

Thanks a lot for this detailed explanation!!! Helps a lot. I just ordered my Theatre+8s on Friday, so your timing is almost as perfect as the post itself :)
I’ll do it like you did, for now without 28s but hopefully soon they’ll be on the list as well.

Great to hear! I’m sure yo will be happy with it. And please don’t hesitate to ask me any questions after you have received it.

I can also recommend you to join the Discord group BeoTalk.
https://discord.gg/Th8pCan2h

it complements this forum but is much more active when it comes to new B&O products, like the Theatre and BL8. There are also a knowledge library and setup guides for e.g Theatre.

You are naturally welcome to ask any questions here as well. I was late into B&O buying the BL28 as my first B&O products, which I bought due to its sound and design. However, what really got me to ”invest into the brand” and get the Theatre, BL8 and BS2  was the great community around the brand, both here and especially on the Discord group (as I only have new Mozart products). The willingness to help each other is quite unique. This was not something I had experienced with my previously owned HiFi brands.

Congratulations to your purchase!